The present invention relates generally to a stacked semiconductor package.
Semiconductor chips that can quickly store and process a large volume of data can be included in a semiconductor package. A stacked semiconductor package having at least two stacked semiconductor chips on a substrate can improve not only the data storage capacity but also the data processing speed. The stacked semiconductor chips in a package need to be electrically connected to the substrate. Wire bonding method using wires and a flip-chip bonding method using bumps are two well known methods to accomplish the intended electrical connections.
Although the wire bonding method using wires for electrical connection is frequently used in a stack structure, it has a drawback in that the length of each wire electrically connecting each additional stacked chip is inevitably lengthened. This causes the signal transfer lengths to increase, which in turn deteriorates the electrical characteristics of the package and causes enlargement of the package size. Also, defects known as “sweeping of wires” can occur due to the increasingly lengthened wires. The flip-chip bonding method provides shorter signal transfer lengths than the wire bonding method, but it has been generally regarded as a difficult method achieving high integration due to certain limitations that hinder stacking.